Search results for "integral transform"

showing 10 items of 18 documents

Regularity of the solution to a class of weakly singular fredholm integral equations of the second kind

1979

Continuity and differentiability properties of the solution to a class of Fredholm integral equations of the second kind with weakly singular kernel are derived. The equations studied in this paper arise from e.g. potential problems or problems of radiative equilibrium. Under reasonable assumptions it is proved that the solution possesses continuous derivatives in the interior of the interval of integration but may have mild singularities at the end-points.

Algebra and Number TheoryMathematical analysisFredholm integral equationSingular integralIntegral transformFredholm theoryIntegral equationsymbols.namesakeSingular solutionsymbolsGravitational singularityDifferentiable functionAnalysisMathematicsIntegral Equations and Operator Theory
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A generalized integration formula for indefinite integrals of special functions

2020

An integration formula for generating indefinite integrals which was presented in Conway JT [A Lagrangian method for deriving new indefinite integrals of special functions. Integral Transforms Spec...

Differential equationApplied Mathematics010102 general mathematicsMathematicsofComputing_NUMERICALANALYSIS010103 numerical & computational mathematicsIntegral transform01 natural sciencesAlgebraVDP::Teknologi: 500symbols.namesakeTheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGESSpecial functionsComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATIONsymbols0101 mathematicsAnalysisLagrangianMathematicsIntegral Transforms and Special Functions
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Determination of relaxation and retardation spectrum by inverse functional filtering

2010

Abstract The article is devoted for the determination of the relaxation and retardation spectrum (RRS) from monotonic time- and frequency-domain material functions by the inverse functional filters executing discrete convolution algorithms for geometrically spaced data. It is shown that the problem of RRS determination from a wide variety of material functions leads to the three inverse filtering tasks on a logarithmic time or frequency scale with the three specific frequency responses concerning: (i) the time-domain functions, (ii) the real parts and (iii) the imaginary parts of the frequency-domain functions, and three algorithms (having the versions with even and odd number of coefficien…

Frequency responseLogarithmApplied MathematicsMechanical EngineeringGeneral Chemical EngineeringInverse filterInverseMonotonic functionInverse problemCondensed Matter PhysicsIntegral transformGeneral Materials SciencePoint estimationAlgorithmMathematicsJournal of Non-Newtonian Fluid Mechanics
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Henstock type integral in harmonic analysis on zero-dimensional groups

2006

AbstractA Henstock type integral is defined on compact subsets of a locally compact zero-dimensional abelian group. This integral is applied to obtain an inversion formula for the multiplicative integral transform.

Henstock integralApplied MathematicsMathematical analysisLine integralRiemann integralRiemann–Stieltjes integralSingular integralLocally compact groupHenstock–Fourier seriesVolume integralsymbols.namesakeLocally compact zero-dimensional abelian groupImproper integralsymbolsCharacters of a groupInversion formulaDaniell integralMultiplicative integral transformAnalysisMathematicsJournal of Mathematical Analysis and Applications
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Integration of functions ranging in complex Riesz space and some applications in harmonic analysis

2015

The theory of Henstock—Kurzweil integral is generalized to the case of functions ranging in complex Riesz space R and defined on any zero-dimensional compact Abelian group. The constructed integral is used to solve the problem of recovering the R-valued coefficients of series in systems of characters of these groups by using generalized Fourier formulas.

Henstock integralSeries (mathematics)Riesz representation theoremRiesz potentialintegral transformGeneral MathematicsMathematical analysisMathematics::Classical Analysis and ODEsHilbert spacegroup characterRiesz spacezero-dimensional compact Abelian groupcharacterHenstock—Kurzweil integralComplex Riesz space character Henstock integral basis integral transform.Riesz transformsymbols.namesakeFourier transformM. Riesz extension theorembasissymbolsMathematics (all)complex Riesz spaceMathematicsMathematical Notes
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Radon transform as a set of probability distributions

2009

It is proved that the Radon transform of the Wigner function gives the probability distributions related to measuring the observable operators obtained as linear combinations of position and momentum of the relevant particle. The generalization to an arbitrary number of degrees of freedom is given.

Integral transformsOptical tomographySettore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciRadon transformCharacteristic function (probability theory)Mathematical analysisWigner semicircle distributionCondensed Matter PhysicsConvolution of probability distributionsAtomic and Molecular Physics and OpticsSettore FIS/03 - Fisica Della MateriaRegular conditional probabilityProbability distributionWigner distribution functionQuantum tomographyMathematical PhysicsMathematicsK-distribution
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Inversion formulae for the integral transform on a locally compact zero-dimensional group

2009

Abstract Generalized inversion formulae for multiplicative integral transform with a kernel defined by characters of a locally compact zero-dimensional abelian group are obtained using a Kurzweil-Henstock type integral.

Locally compact zero-dimensional abelian group characters of a group Kurzweil-Henstock integral Fourier series multiplicative integral transform inversion formulaSettore MAT/05 - Analisi MatematicaGeneral MathematicsMultiplicative functionMathematical analysisMathematics::Classical Analysis and ODEsLocally compact spaceAbelian groupLocally compact groupIntegral transformInversion (discrete mathematics)MathematicsTatra Mountains Mathematical Publications
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Digital signal processing for relaxation data conversion

2005

Abstract The origins, philosophy and basic practical aspects are considered for an approach of digital data transformations for broadband dielectric relaxation spectroscopy and other relaxation experiments carrying out direct and inverse integral transforms with kernels depending on the ratio or product of arguments. The approach is based on the concept that the mentioned data transformations represent a filtering problem on a logarithmic scale allowing one to implement the transforms by digital functional filters with the logarithmic sampling. As an example, digital Kramers–Kronig transformers are considered.

Logarithmic scaleSignal processingLogarithmComputer sciencebusiness.industryDigital datacomputer.file_formatCondensed Matter PhysicsIntegral transformElectronic Optical and Magnetic MaterialsData conversionMaterials ChemistryCeramics and CompositesFiltering problembusinessAlgorithmcomputerDigital signal processingJournal of Non-Crystalline Solids
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On the translation of the three fundamental problems of elastic equilibrium of anisotropic bodies into systems of Fredholm first kind integral equati…

1972

Mechanical EngineeringMathematical analysisFredholm integral equationSummation equationCondensed Matter PhysicsTranslation (geometry)Integral transformFredholm theoryIntegral equationVolterra integral equationsymbols.namesakeMechanics of MaterialsImproper integralsymbolsMathematicsMeccanica
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Heuristic Algorithm for the Analysis of Fast Field Cycling (FFC) NMR Dispersion Curves

2021

Evaluation of nuclear magnetic relaxation dispersion (NMRD) curves obtained by the fast field cycling nuclear magnetic resonance (FFC-NMR) relaxometry technique is a valuable tool for analyzing the microscopic dynamics of condensed matter systems. However, quantitative data analysis involves several conceptual and practical issues. Moving forward from previous literature approaches, we propose a new analysis method, relying on the elaboration of the inverse integral transform of the NMRD curve. Our approach results in a true heuristic method, able to unambiguously individuate the dynamic domains in the system, thereby avoiding the possible introduction of any element of discretion. The anal…

Nuclear magnetic relaxationNanospongesRelaxometryMagnetic Resonance SpectroscopyField cyclingHeuristic (computer science)Settore AGR/13 - Chimica AgrariaInverseHeuristic algorithm010402 general chemistry01 natural sciencesAnalytical ChemistryFFC NMRCheeseDispersion (optics)HeuristicsAnalysis methodSettore CHIM/02 - Chimica FisicaCyclodextrinsChemistry010401 analytical chemistrySettore CHIM/06 - Chimica OrganicaIntegral transformMagnetic Resonance Imaging0104 chemical sciencesRelaxometryAlgorithmAlgorithmsAnalytical Chemistry
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